CN1229423C - Condensation method of compounds containing silicon-bonded hydroxyl or alkoxy groups - Google Patents

Abstract

The specification describes preparation of materials comprising selected boron anions and processes using them as catalysts for condensation reaction of compounds having silicon-bonded hydroxy or alkoxy groups. Preferred anion compounds comprise borates incorporating quadri-substituted boron in which the substituents include highly halogenated hydrocarbon groups for example pentafluorinated phenyl groups or bis(trifluoromethyl) phenyl groups. Preferred anions are {B(C6F5)4}<-> and {B(C6(CF3)2H3)4}<->. The specification describes condensation in presence of these materials of compounds having at least one unit according to the general formula (I): R DEG aR<1>bR<2>cSiO(4-(a+b+c)/2) in which each R DEG is the same or different and represents a hydroxy, alkoxy, alkoxyalkoxy or hydrocarbonoxy group having up to 10 carbon atoms, each R<1> is the same or different and represents hydrogen or a monovalent substituted or unsubstituted hydrocarbon group, each R<2> is the same or different and represents a divalent substituted or unsubstituted alkylene or oxyalkylene group, <i>a</i> has a value of 1, 2, 3, or 4, <i>b</i> has a value of 0, 1, 2 or 3 and <i>c</i> has a value of 0, 1, 2 or 3.

Description

Condensation method of compounds containing silicon-bonded hydroxyl or alkoxy groups

technical field

The present invention relates to the chemical reaction of compounds containing silicon-bonded hydroxyl or alkoxy groups by condensation reactions.

Background technique

It is well known that chain extension and crosslinking reactions of silicon-containing compounds can be readily achieved by condensation of silicon-bonded hydroxyl, alkoxy or other condensable groups present in the compound or formed therein, for example, during the condensation process. These reactions can be, for example, according to the following schemes:

,or

     

Wherein R represents a substituted or unsubstituted, saturated or unsaturated hydrocarbon group.

Such reactions are used in commerce, especially in the preparation of polydiorganosiloxanes of increased molecular weight, and in the production of various silicon compounds in one or more parts for a wide range of applications. In formulations of oxane compounds where it is desired that the compound be cured in situ to a crosslinked state. By condensation, silanols comprising oligomers HO(SiMe ₂ O) _n H (where Me represents methyl CH ₃ and the value of n is, for example, from about 4 to about 40) are used to form Polymerization of silicone polymers with values in excess of 1,000) is a very important part of the process of making silicone polymer materials with viscosities ranging from those of fluids to those of gums. It is known that this chain extension process can be performed batchwise or continuously. The reaction is typically carried out in the presence of one or more catalyst materials.

Various acidic and basic materials are known to be used as reaction catalysts for silicone materials through silanol condensation reactions, such as potassium hydroxide, ammonium hydroxide, barium hydroxide, acidic clays, sulfonic acids, and phosphazene bases. However, these catalysts tend to catalyze other reactions simultaneously besides the condensation reaction and a consequence may be the presence of a significant proportion of cyclic siloxanes in the product. Likewise, catalysts are required to function consistently and should be able to be removed from the product (along with other undesirable residues), and those used in continuous production processes are required to function rapidly. One type of material suggested for the preparation of siloxanes with increased molecular weight is phosphazene chloride. Although these materials have many advantages as catalysts for the polymerization of silicone materials, they are produced and used in chlorinated solvents, which are considered potentially environmentally hazardous and therefore require special handling. It is also quite difficult to neutralize consistently in polymer production. In addition, phosphazene chloride is prone to hydrolysis and loss of catalytic activity upon prolonged exposure to water.

Furthermore, prior art document GB1172661A discloses a novel quaternary ammonium and phosphonium boron complex, but there is no teaching that this complex can be used for the condensation of compounds containing silicon-bonded hydroxyl or alkoxy groups. However, the prior art documents JP9-194816A, JP9-208925A and WO9829498A1 do not disclose the condensation method of compounds containing silicon-bonded hydroxyl groups or alkoxy groups.

Therefore, despite many proposals for catalyst materials for these condensation reactions, there is still a need to provide a material which can be used as an effective catalyst, which can be prepared by a simple process and which does not leave difficult Neutralized or stripped residues.

Contents of the invention

Surprisingly, we have found that the condensation of compounds containing silicon-bonded hydroxyl or alkoxy groups can be achieved in the presence of catalytic amounts of one or more materials which provide a source of anions comprising at least one tetrasubstituted boron atom and A proton capable of interacting with at least one silanol group.

The present invention in one of its aspects provides a process for the condensation of compounds containing silicon-bonded hydroxyl or alkoxy groups in the presence of a catalytic amount of one or more materials which provide in the reaction mixture a compound comprising at least one tetrasubstituted An anion of a boron atom and a proton capable of interacting with at least one of the silicon-bonded hydroxyl or alkoxy groups.

In the method according to the invention it is important that the boron-containing anion itself does not directly form a covalent bond to the silicon atom and that it does not decompose or rearrange to produce an anion which directly forms a covalent bond to the silicon atom. Suitable materials include those containing one or more boron atoms in a radical and several, eg ten or more, halogen atoms attached to each boron atom. The halogen in such compounds may be attached to the boron atom through a linkage involving at least one carbon atom. The halogen atoms are preferably selected from fluorine, chlorine and bromine, most preferably fluorine. Preferred anions include one or more boron atoms having four organic substituents thereon, most preferably tetrasubstituted borates. The organic substituent is suitably a hydrocarbyl group. Three and preferably four of these hydrocarbyl groups are preferably aromatic groups, and are preferably highly halogenated. Preferred halohydrocarbons are pentafluorophenyl and bis(trifluoromethyl)phenyl and preferred materials contain four such groups bonded to each boron atom. One effective material is the tetrakis(pentafluorophenyl)borate anion (otherwise referred to herein as the pentafluoroarylborate anion) and the material is preferably the acid of this anion, namely H ⁺ {(C ₆ F ₅ ) ₄ B} ^- Form used. Other effective materials include those containing two tetrasubstituted boron atoms eg, di-perfluorinated aryl borate anions such as H ⁺ {B(C ₆ F ₅ ) ₃ CNB(C ₆ F ₅ ) ₃ } ⁻ . Preferred materials are readily prepared from commercially available compounds by simple ion exchange techniques in harmless solvents such as water or alcohols. We prefer to prepare the acids before introducing catalytic amounts of them into the reaction mixture.

Other suitable boron-containing anions for use in the method of the invention include carboranes, for example having the general formula {CB ₉ H ₁₀ } ⁻ , {CB ₉ X ₅ H ₅ } ⁻ , {CB ₁₁ H ₁₂ } ⁻ , and {CB ₁₁ X ₆ H ₆ } ^- , wherein X represents fluorine, chlorine, bromine or iodine. Carboranes may contain more highly substituted than tetrasubstituted boron atoms, such as pentasubstituted and hexasubstituted boron atoms, and for clarity, "tetrasubstituted" as used herein is intended to include those anions containing tetrasubstituted and higher substituted boron atoms .

In the methods according to the invention, one may employ any suitable compound containing silicon-bonded hydroxyl or alkoxy groups. Preferred materials are silane and siloxane compounds containing at least one unit according to the general formula:

(i) R ⁰ _a R ¹ _b R ² _c SiO _{(4-(a+b+c)/2)}

wherein each R ⁰ represents a hydroxyl group, an alkoxy group, an alkoxyalkoxy group or an alkoxy group containing up to 10 carbon atoms, each R ¹ represents a hydrogen atom or a monovalent substituted or unsubstituted hydrocarbon group, each R ² represents a divalent substituted or unsubstituted alkylene group, or an oxyalkylene group bonded to an atom of a polymeric material, for example another unit of general formula (i) or as represented below, a has a value of 1, 2, 3 Or 4, b has the value 0, 1, 2 or 3 and c has the value 0, 1, 2 or 3 and a+b+c has the value 1, 2, 3 or 4. Suitable groups R ⁰ include, for example, hydroxy, methoxy, ethoxy, butoxy, phenoxy, and methoxyethoxy. Suitable ^R include, for example, hydrogen, alkyl such as methyl, ethyl, propyl, isobutyl, hexyl, dodecyl or octadecyl, alkenyl such as vinyl, allyl, Butenyl, hexenyl or decenyl, alkynyl such as propargyl, aryl such as phenyl, aralkyl such as tolyl or xylyl, substituted hydrocarbon such as trifluoropropyl, chloropropyl or chlorobenzene base. Suitable groups R ² include, for example, -(CH ₂ ) _n -, where n has a value of 1, 2, 3 or greater and -(OCH ₂ CHR ³ ) _m -, where R ³ represents H or -CH ₃ and The value of m is greater than about 5. Compounds containing at least one unit according to general formula (i) may be monomeric, oligomeric or polymeric. The monomeric material is preferably a silane in which the value of c is 0 and the value of a+b is 4. The polymeric material may be predominantly organic or predominantly silicone. Examples of suitable predominantly organic materials are those in which one or more units of the general formula (i) are introduced into an organic polymer via its divalent radical R ² . Examples of principal siloxane materials are polymers incorporating units according to general formula (ii) R ¹ _s SiO _(4-s)/2 , wherein R ¹ is as previously described and s has a value of 0, 1, 2 or 3. Preferably, a substantial proportion (preferably greater than 80%) of these units are those in which s has a value of two. These polymers may, if desired, contain one or more units of general formula (i) attached via their divalent linkage ^R2 to the silicon atom of the polymer.

In the process according to the invention, a compound containing silicon-bonded hydroxyl or alkoxy groups can be condensed with itself, with one or several other compounds containing silicon-bonded hydroxyl or alkoxy groups. By suitable variation of a, b and c values and groups R ⁰ , R ¹ , R ² , one can induce condensation reactions to provide products of various molecular sizes, functionalities and reactivity, which are thus suitable for a wide range of uses . As stated, compounds according to the general formula R ⁰ _a R ¹ _b R ² _c SiO _(4-(a+b+c)/2 may contain one or more groups R ⁰ . In the method according to the invention, The combination of the first of these compounds with the second of these compounds can be caused by one ^R group of each compound. In this way, the first of these compounds can be employed to consume the ^R group of the second compound and introducing the desired radical into a second compound. For example, in the case where the first compound is a silane of general formula (i) and the second compound is a polymer containing units of general formula (i), by With a suitable choice of the value of a, one can bring about chain extension, chain branching or chain termination condensation reactions in which the paired radical R is consumed. Also by suitable choice of the value of a and the value of b, the ^{group R} can be introduced into the chain In or its terminus. Interesting is the introduction of alkenyl groups in this way, as it provides a route to react through their unsaturation.

Particularly suitable materials containing silicon-bonded hydroxyl or alkoxy groups include, for example, dihydroxy or alkoxy α,ω-dihydroxy-polydimethylsiloxanes according to the general formula HO(SiMe ₂ O) _n H, where Me Represents a methyl group and n has a value from about 4 to about 40; polydimethyl according to the general formula Me ₃ SiO(SiMe ₂ O) _n SiMe ₃ (where Me represents methyl CH ₃ and n has a value from 0 to 100) Silicone; diethoxymethylvinylsilane; ethoxydimethylvinylsilane; and methoxydimethylhexenylsilane; and mixtures of two or more thereof.

In the method according to the invention, a compound or compounds containing silicon-bonded hydroxyl or alkoxy groups is provided as the host of the material. In cases where polymer production is to be performed, the bulk is confined to reaction vessels of the batch or continuous type. Where one wishes to provide the group ^R0 on the compound by conversion of other groups such as Cl or CN, this can be done as a separate step or less preferably in the reactive body of the material. If more than one silicon-bonded hydroxyl or alkoxy-containing compound is to be employed, the compounds can be introduced into the reaction vessel in any desired order. The catalysts are introduced into the reaction body in any desired order and the condensation reaction is carried out at any desired temperature and pressure. The reaction can be carried out at room temperature or elevated temperature, with or without reduced pressure. The catalyst can be used at a concentration of 1-500 ppm by weight, based on total reactants. The amount used can be changed according to the temperature used for the reaction. At room temperature we prefer to use 100-500 ppm and for reactions at 80°C we prefer to use 1-30 ppm.

Specifically, the present invention provides a condensation method of a compound containing a silicon-bonded hydroxyl or alkoxy group, characterized in that the compound containing a silicon-bonded hydroxyl or alkoxy group is selected from one or more of the following compounds: α,ω-dihydroxy-polydimethylsiloxanes of the general formula HO(SiMe ₂ O) _n H, where Me represents a methyl group and n has a value from 4 to 40; of the general formula Me ₃ SiO(SiMe ₂ O ) _n SiMe ₃ polydimethylsiloxanes, where Me represents methyl and n has a value from 0 to 100; ethoxydimethylvinylsilane; methoxydimethylhexenylsilane; and di Ethoxymethylvinylsilane; and the method is carried out at 1-500ppm in the presence of a catalyst comprising a proton and an anion, the anion being {B(C ₆ F ₅ ) ₄ } ⁻ , {B(C ₆ (CF ₃ ) ₂ H ₃ ) ₄ } ^- or H ⁺ {B(C ₆ F ₅ ) ₃ CNB(C ₆ F ₅ ) ₃ } ^- .

Various materials may be present in the reaction mixture as desired, for example, solvents, reinforcing or filling fillers, cocatalysts, pigments, plasticizers, extenders or mixtures of any two or more thereof, provided that always They do not adversely affect the reaction.

The present invention is concerned with the homocondensation or cocondensation of materials containing silicon-bonded hydroxyl, or alkoxy groups and employs particularly, but not exclusively, those which are particularly effective for use with materials containing all compounds derived from silanols, by batch or continuous processes. Preparation of higher molecular weight linear or branched polymeric silicone materials requiring pendant or terminal groups. The catalyst materials used in the present invention are shown to catalyze condensation reactions if and so long as condensable co-reactants are present. When such co-reactants are not present in sufficient amounts, these catalyst materials are capable of catalyzing the re-equilibration of the polymer formed to give lower molecular weight polymer mixed with the cyclic siloxane. When no longer needed, catalytic activity can be terminated, for example by neutralizing the catalyst material with basic substances, such as organic amines, preferably alkylamines, or by heating to decompose the catalyst. This can be done at any stage of the process, for example when the desired viscosity has been reached and before significant rebalancing can take place.

The method according to the invention offers various advantages over prior known processes. The catalyst materials are stable to water and alcohols and their catalytic activity is not significantly reduced by exposure to water and alcohols. The preparation of the catalyst and the introduction of the catalyst into the polymerization reaction without the use of chlorinated solvents makes the production and use of the catalyst more environmentally acceptable. Not only due to the absence of chloride anions but also due to the ease of neutralizing the catalyst, reducing the presence of undesired residual catalyst and compounds derived therefrom in the reaction product. Thus, for example, due to the absence of chlorinated solvents from the catalyst, at least substantially linear polydiorganosiloxanes can be produced in a cleaner manner and the process can be controlled so that at least Essentially linear polydiorganosiloxane.

As used herein, the word "comprising" is intended to mean the concept of including as well as the concept of consisting of.

Example

In order to make the present invention clearer, a description is given below of Examples, which are selected to illustrate the present invention by way of examples. In these examples, unless the context dictates otherwise, the symbol Et denotes ethyl, He denotes hexenyl, Me denotes methyl, Ph denotes phenyl, Vi denotes vinyl, all parts by weight and all viscosities at Measured and expressed as centipoise (1 Poise = 0.1 Pa.s) at 25°C.

Example 1

Various materials for providing (a) a source of protons capable of interacting with at least one silanol group and (b) a boron-containing anion were prepared as follows.

Materials comprising the acid H ⁺ {B(C ₆ F ₅ ) ₄ } ^- were prepared by two different methods, neither of which involved the use of halogenated solvents. In the first method, 0.204 g of the anilinium salt {PhNHMe ₂ } ⁺ {B(C ₆ F ₅ ) ₄ } ^- was dissolved in 4 cc of a 50:50 mixture by volume of ethanol and water and 1 g of Amberlist 15 was added for ion exchange resin. The mixture was shaken gently for 5 minutes and then allowed to stand with occasional shaking for 2 hours at room temperature. The ion exchange resin was filtered off and washed with a methanol water mixture (50:50 by volume) to give a total volume of filtrate and washes of 10 cc. By titration, this liquid was found to contain an amount of acid corresponding to complete conversion of the anilinium salt to the acid H ⁺ {B( _C6F5 ) ₄ } _- ^. This mixture was used as illustrative catalyst material 1 in the following examples.

In the second method, 0.205 g of the trityl salt CPh ₃ ⁺ {B(C ₆ F ₅ ) ₄ } ^- was heated in 45 cc of water at 50°C for 30 minutes, during which time the yellow trityl The base salt dissolves slowly, producing an insoluble white precipitate and a colorless liquid. The mixture was allowed to cool and made up to 50cc with water. By titration, the liquid was found to contain an amount of acid corresponding to the complete conversion of the trityl salt to the acid H ⁺ {B(C ₆ F ₅ ) ₄ } ^- . This liquid was used as illustrative catalyst material 2 in the following examples.

A material comprising the acid H ⁺ {B(C ₆ (CF ₃ ) ₂ H ₃ ) ₄ } ^- was prepared by dissolving 0.204 g of the sodium salt {Na} ⁺ {B in 2 cc of a 50:50 by volume mixture of ethanol and water (C ₆ (CF ₃ ) ₂ H ₃ ) ₄ } ^- and 1 g of Amberlist 15 ion exchange resin was added. The mixture was shaken gently for 5 minutes and then allowed to stand with occasional shaking for 2 hours at room temperature. The ion exchange resin was filtered off and washed with a methanol water mixture (50:50 by volume) to give a total volume of filtrate and washes of 5 cc. By titration, this liquid was found to contain an amount of acid corresponding to the complete conversion of the sodium salt to the acid H ⁺ {B(C ₆ (CF ₃ ) ₂ H ₃ ) ₄ } ⁻ . This liquid was used as illustrative catalyst material 3 .

Example 2

In the presence of a perfluorinated aryl borate catalyst H ⁺ {B(C ₆ F ₅ ) ₄ } ^- , a series of experiments were performed to demonstrate the polymerization of linear polydiorganosiloxanes into a laboratory batch reactor 1500 parts of a compound containing silicon-bonded hydroxyl or alkoxy groups, namely α,ω-dihydroxy-polydiorganosiloxanes according to the general formula HO(SiMe ₂ O) _n H, wherein n has a value of about 4- About 40 and 44 parts of 10 centipoise siloxane fluid of general formula Me ₃ SiO(SiMe ₂ O) _n SiMe ₃ (wherein the value of n is 0-100), and stirring while heating to 60°C-100°C required temperature and required pressure. When the mixture had stabilized, illustrative catalyst material 1 as prepared in Example 1 was introduced at the desired concentration of 1 ppm to 30 ppm of the reaction mixture (ie 1.1168 10 ⁻⁶ to 3.23872 10 ⁻⁵ moles of anions per liter of reaction mixture). The reaction was allowed to proceed and monitored by continuous plotting of stirrer torque, silanol content and viscosity with elapsed time. As the reaction proceeds, the silanol content decreases, the viscosity increases to a maximum and then decreases as endcapping occurs. The reaction was stopped by passing the reaction mixture into a bottle containing triethylamine. The reaction product was identified as a polydiorganosiloxane according to the general formula _Me3SiO ( _SiMe2O ) _nSiMe3 and using _NMR analysis, the catalyst was confirmed to be unchanged.

The results of the series of tests are shown in Tables 1 and 2. Table 1 shows the relative initial rates of silanol condensation at various pressures and temperatures using a uniform catalyst concentration of 2.23 moles per liter (i.e., 20 ppm), as measured by the reduction in silanol loss peak area using Fourier transform infrared spectroscopy. , determined from the loss of silanols. It can be appreciated that, in general, the initial rate of silanol condensation is greater at higher temperatures and lower pressures, and a temperature of 80 °C and 10 mbar is effective.

Table 1 temperature pressure 60℃ 80°C 100°C 1,000 mbar 1 4.41 19.89 75 mbar 2.07 15.72 34.98 10 mbar 8.04 16.50 34.25

Table 2 shows the relative initial rates of silanol condensation determined as described above using a temperature of 80°C and a pressure of 10 mbar and various catalyst concentrations. It can be appreciated that the silanol condensation proceeds faster in the presence of increasing amounts of catalyst material.

Table 2 catalyst level ppm catalyst Catalyst concentration (mol/L) Relative initial rate of silanol condensation 1.0 1.1168 10 ^-6 0.36 5.0 5.8400 10 ^-6 1.00 10.0 1.11680 10 ^-5 1.43 15.0 1.67520 10 ^-5 1.71 20.0 2.23360 10 ^-5 1.90 29.0 3.23872 10 ^-5 2.23

Similar results were obtained when this polymerization procedure was repeated using illustrative catalyst materials 2 and 3 instead of illustrative catalyst material 1 at a temperature of 80°C and a pressure of 10 mbar. Similar results were obtained when at a temperature of 80° C. and a pressure of 10 mbar using illustrative catalyst material 1 which had been stored at ambient temperature and pressure in a sealed volumetric flask containing air for three months.

Example 3

This example demonstrates the preparation of a fourth illustrative catalyst material, Et ₃ Si ⁺ {B(C ₆ F ₅ ) ₄ } ^— , and their use for polymerizing silanols in the absence of water. Triethylsilane was added to a solution of CPh ₃ ⁺ {B(C ₆ F ₅ ) ₄ } ^- in dichloromethane (total volume 10 cm ³ ) at room temperature. After a slight outgassing, a pale orange solution was obtained, 0.4 ^cm of this solution was added to 100 g of α,ω-dihydroxy-polydiorganosiloxane according to the general formula HO(SiMe ₂ O) _n H, wherein the value of n is from about 4 to about 40. The polysiloxane increased in viscosity to a gum-like consistency within 3 minutes. Furthermore, when a 20 ppm solution is used as catalyst in the procedure described in Example 2 at a temperature of 65° C. and a pressure of 75 mbar, the polysiloxane polymerizes readily.

Example 4

This example demonstrates the heterocondensation of linear polydiorganosiloxanes and vinylalkoxysilanes in the presence of a perfluorinated aryl borate catalyst H ⁺ {B(C ₆ F ₅ ) ₄ } ^- . A laboratory batch reactor was charged with 1500 parts of an α,ω-dihydroxy-polydiorganosiloxane according to the general formula HO( _SiMe2O ) _nH , where n has a value from about 4 to about 40 and 8.78 parts of B oxydimethylvinylsilane and stirred while heating to 60 °C at atmospheric pressure. When the mixture had stabilized, 20 ppm of illustrative catalyst material 1 was introduced (ie 2.2336 10 ^-5 moles per liter of reactant). The reaction was allowed to proceed and monitored by continuous plotting of stirrer torque, silanol content and viscosity with elapsed time. After 5 minutes of reaction at atmospheric pressure, the pressure was reduced to 75 mbar and the reaction was continued for 40 minutes, during which time the viscosity of the reaction mixture increased and stabilized. The reaction was neutralized by passing the reaction mixture into a bottle containing triethylamine. The reaction product was identified as a polydiorganosiloxane with _a viscosity of 4840 (Brookfield viscosity) according to the general formula _ViMe2Si ( _SiMe2O ) _nSiMe2Vi . Analysis of _the product showed a content of less than 0.2% cyclic siloxanes, less than 0.1% silanols and less than 0.1% _SiOCH2CH3 groups. When the reaction was repeated at 80°C with the same amount of the same material, except that half the amount of ethoxydimethylvinylsilane was used, the product was confirmed to have a viscosity of 29,930 (Brookfield viscosity) according to the general formula _ViMe2Si (SiMe ₂ O) _n SiMe ₂ Vi polydiorganosiloxane. Analysis of the product showed less than 1% cyclic siloxane content.

Example 5

This example demonstrates the heterocondensation of linear polydiorganosiloxanes and alkenylalkoxysilanes in the presence of a perfluorinated aryl borate catalyst H ⁺ {B(C ₆ F ₅ ) ₄ } _- . A laboratory batch reactor was charged with 1500 parts of an α,ω-dihydroxy-polydiorganosiloxane according to the general formula HO(SiMe ₂ O) _n H, where n has a value from about 4 to about 40 and at 75 mM heated to 60°C under bar pressure. When the mixture had stabilized, the vacuum was released and 4.65 parts of methoxydimethylhexenylsilane and then 20 ppm (ie 2.2336 10 ⁻⁵ moles per liter of reactant) of Illustrative Catalyst Material 1 were introduced and vacuum applied. The reaction was allowed to proceed and monitored by continuous plotting of stirrer torque, silanol content and viscosity with elapsed time. After 20 minutes at 75 mbar, the reaction mixture increased in viscosity and stabilized. The reaction was neutralized by passing the reaction mixture into a bottle containing triethylamine. The reaction product was identified as _a polydiorganosiloxane having a viscosity greater than 65,000 according to the general formula _HeMe2Si ( _SiMe2O ) _nSiMe2He . Analysis of the product showed a cyclic siloxane content of 0.36%.

Example 6

This _example demonstrates _the ^{heterocondensation} of linear ^{polydiorganosiloxanes} _and vinyldialkoxysilanes containing Preparation of pendant polymers. A laboratory batch reactor was charged with 1500 parts of an α,ω-dihydroxy-polydiorganosiloxane according to the general formula HO( _SiMe2O ) _nH , where n has a value from about 4 to about 40 and 46 parts of Me ₃ SiO(SiMe ₂ O) _n SiMe ₃ (n=0-100) and 11.8 parts of diethoxymethylvinylsilane and stirring while heating to 80° C. under atmospheric pressure. When the mixture had stabilized, 20 ppm (ie 2.2336 10 ⁻⁵ moles per liter of reactant) of illustrative catalyst material 1 was introduced. The mixture was stirred for 60 minutes and the reaction was allowed to proceed and monitored by continuous plotting of stirrer torque, silanol content and viscosity with elapsed time. After 60 minutes of reaction at atmospheric pressure, the pressure was reduced to 75 mbar and the reaction was continued for 60 minutes, during which time the viscosity of the reaction mixture increased and stabilized. The reaction was neutralized by passing the reaction mixture into a bottle containing triethylamine. The reaction product was confirmed to have a viscosity of 3225 (Brookfield viscosity) according to the general formula (CH ₃ ) ₃ SiO(Si(CH ₃ ) ₂ O) ₅₇₀ (SiCH ₃ Vi) _1.42 Si(CH ₃ ) ₃ polydiorganosiloxane . Analysis of the product showed a content of 1% cyclic siloxane, and _a small amount of _SiOCH2CH3 groups.

Example 7

A laboratory batch reactor was charged with a mixture of 1500 parts of an α,ω-dihydroxy-polydiorganosiloxane according to the general formula HO(SiMe ₂ O) _n H, where n has a value from about 4 to about 40 and 9.1 parts capping agent according to the general formula ViMe ₂ SiO(SiMe ₂ O) ₈ SiMe ₂ Vi. The mixture was heated to 80° C. under vacuum at a pressure of 10 mbar. When the reaction mixture had stabilized, illustrative catalyst material 1 was introduced thereto at the desired temperature at a concentration of 20 ppm (2.2336e ^-5 mol/liter). The reaction was monitored by online measurements of stirrer torque, silanol content, and viscosity. Water was seen to be removed from the reaction in the form of water vapor, causing the reaction to foam with a concomitant increase in viscosity and decrease in silanol concentration as measured by the on-line probe. The viscosity of the reaction reaches a maximum as condensation proceeds and then decreases as capping continues. After 15 minutes the reaction was neutralized by passing the reaction mixture into a bottle containing a small amount of triethylamine (0.05 parts). Using these ratios of starting materials, vinyl terminated polymers 4 _, 5 and 6 according to the general formula _ViMe2SiO ( _Me2SiO ) _nSiMe2Vi were prepared. The values of viscosity, silanol content and n from NMR measurements and the number average molecular weight of the polymers (measured by GPC) are shown in Table 3.

This procedure was repeated using the following mass heated to 80° C. under vacuum at a pressure of 10 mbar: 1500 parts of α,ω-dihydroxy-polydiorganosiloxanes according to the general formula HO(SiMe ₂ O) _n H, where n is Values range from about 4 to _about 40 and 2764 parts capping agent according to the general formula _ViMe2SiO ( _SiMe2O ) _8SiMe2Vi . When the reaction mixture had stabilized at the desired temperature, the first illustrative catalyst was introduced into the mixture at a concentration of 20 ppm (2.23360e ^-5 mol/liter). Vinyl terminated polymers 4, 5 and 6 were prepared using these ratios of starting materials. The values of viscosity, silanol content and n from NMR measurements and number average molecular weight (GPC) of the polymers are shown in Table 3.

Example 8

A laboratory batch reactor was charged with a mixture of 1500 parts of an α,ω-dihydroxy-polydiorganosiloxane according to the general formula HO(SiMe ₂ O) _n H, where n has a value from about 4 to about 40 and 10 parts polysiloxanes _containing silicon-bonded hydrogen atoms according to the general formula _HSiMe2O ( _SiMe2O ) _18SiMe2H . The mixture was heated to 80° C. under vacuum at a pressure of 10 mbar. When the reaction mixture had stabilized at the required temperature, the first illustrative catalyst was introduced into the mixture at a concentration of 20 ppm (2.23360 10 ⁻⁵ mol/l). The reaction was monitored by online measurements of stirrer torque, silanol content, and viscosity. Water was seen to be removed from the reaction in the form of water vapor, causing the reaction to foam with a concomitant increase in viscosity and decrease in silanol concentration as measured by the on-line probe. The viscosity of the reaction reaches a maximum as condensation proceeds and then decreases as capping continues. The reaction was neutralized after 10 minutes by passing the reaction mixture into a bottle containing a small amount of triethylamine (0.05 parts). In this way, SiH-terminated polysiloxanes 10 according to the general formula HMe ₂ SiO(Me ₂ SiO) _n SiMe ₂ H were prepared. See Table 3 for the values of viscosity, silanol content, n and polymer number average molecular weight.

In the same manner, by mixing 1500 parts of α,ω-dihydroxy-polydiorganosiloxanes according to the general formula HO(SiMe ₂ O) _n H, where n has a value from about 4 to about 40 and 48 parts of Si- H capping agents HSiMe ₂ O(SiMe ₂ O) ₁₈ SiMe ₂ H and they were heated to 80°C under vacuum at a pressure of 10 mbar, and then the illustrative catalyst was added at a concentration of 5 ppm (5.58400 10 ^-6 mol/l) 1. Preparation of SiH _- terminated polysiloxane 11 according to the general formula _HMe2SiO ( _Me2SiO ) _nSiMe2H . The reaction was monitored by online measurements of stirrer torque, silanol content, and viscosity. The reaction was neutralized after 10 minutes by passing the reaction mixture into a bottle containing a small amount of triethylamine (0.05 parts). See Table 3 for the values of viscosity, silanol content, n and polymer number average molecular weight.

table 3 polymer Viscosity centipoise Final silanol content ppm (NMR) n from NMR Mn (number average molecular weight determined by GPC) Vinyl terminated polymer 1 134,400 97 1389 84,900 Vinyl terminated polymer 2 114,400 147 1,417 69,900 Vinyl terminated polymer 3 158,400 256 666 72,800 Vinyl terminated polymer 4 7300 332 412 37,600 Vinyl terminated polymer 5 9,600 261 448 30,300 Vinyl terminated polymer 6 13,056 296 432 45,300 Si-H terminated polymer 10 6,312 163 541 36,800 Si-H terminated polymer 11 5,850 76 627 37,100

Example 9

In this example, a laboratory reactor was used to demonstrate the condensation reaction of silanols to polymerize polysiloxanes in different solvents in the presence of catalysts in a continuous reactor. The continuous reactor used consisted of a 6 mm diameter helical tube equipped with a heater, inlet pipe and collector vessel.

The borate catalyst H ⁺ {B(C ₆ F ₅ ) ₄ } ^- was prepared in different carrier solvents as follows:

Catalyst A consisting of 0.0115 g of catalyst per 1 ml of water and ethanol mixed in a 1:1 ratio;

Catalyst B consisting of 0.0115 g of catalyst per 1 ml of decanol, ethanol and water in a ratio of 3.5:1:0.5;

Catalyst C consisting of 0.021 g of catalyst per 1 ml of methyl ethyl ketone.

10 parts of α,ω-dihydroxy-polydiorganosiloxane according to the general formula HO(SiMe ₂ O) _n H, wherein n has a value from about 4 to about 40 and 0.12 parts of the general formula Me ₃ SiO(SiMe ₂ O) A mixture of _n SiMe ₃ (where n has a value of 0-100) in 10 centipoise siloxane fluid was mixed while heating to 142°C. The mixture was fed at a rate of 1.7 kg per hour into the helix of the reactor via a venturi along with air under pressure and catalyst A was introduced into the flowing mixture. In separate experiments, Catalyst A was introduced at four different rates, namely 15, 25, 50 and 70 microliters per minute. The collected samples were neutralized with a solution of trihexylamine in cyclomethylpentasiloxane (0.54% N) added at 2 ml/hr. The polymer produced has the general formula Me ₃ SiO(SiMe ₂ O) _n SiMe ₃ . The value of n and the number average molecular weight (Mn) were determined by NMR analysis and the silanol content of the polymer produced was determined as in Example 2. See Table 4 for the values.

Table 4 Catalyst feed rate viscosity n/Mn (by NMR) ppm silanol/% silanol end groups 50μl/min catalyst (20.5ppm) 13,232 420/31,366 640/58.9 20μl/min catalyst (8.2ppm) 18,912 646/48,105 399/56.5 15μl/min catalyst (6ppm) 25,120 570/42,488 460/57.3 70μl/min catalyst (28.8ppm) 12,016 412/30,791 703/63.6

The test was repeated using Catalyst B. The polysiloxane mixture was reintroduced into the reactor at about 142°C and the flow rate was set at about 1.7 kg/hr. Catalyst B was pumped in at a rate of 155 μl/min. The samples were neutralized with a solution of trihexylamine in the cyclopentasiloxane mixture (0.54% N) added at 2 ml/hr. Analysis of the polymer produced gave the results shown in Table 5. The detected alkoxy groups are from the use of decyl alcohol in the catalyst solvent.

table 5 Catalyst feed rate viscosity n/Mn (by NMR) % alkoxy end groups ppm silanol/% silanol end groups 155μl/min(64ppm) 14,955 614/45,627 24.6 208/28.0

This test was repeated using Catalyst C. The polysiloxane mixture was reintroduced into the helical tube of the reactor. The mixture was introduced into the reactor at about 156°C and the flow rate was set at about 1.1 kg/hr. Catalyst C was pumped in at a rate of 25 μl/min. The sample was neutralized again with a solution of trihexylamine in the cyclic pentasiloxane mixture (0.54% N) added at 2.5 ml/hr. Analysis of the polymer obtained as above gave the values shown in Table 6.

The experiment was repeated using a higher flow rate of silicone mixture of 2.5 kg/hr, all other values being equal. Analysis of the polymer obtained as above gave the values shown in Table 6.

Table 6 Silicone mixture feed rate viscosity n/Mn by NMR ppm silanol/% silanol end groups 1.1kg/h (29ppm catalyst) 25,984 693/51,500 299/45 2.5kg/h (12.5ppm catalyst) 19,392 550/40,915 484/58

Example 10

This example shows the preparation of another illustrative catalyst material, H ⁺ {B(C ₆ F ₅ ) ₃ CNB(C ₆ F ₅ ) ₃ } ⁻ . B(C ₆ F ₅ ) ₃ and KCN were weighed and charged into the reaction flask, and diethyl ether was added thereto followed by stirring for 12 hours. The solvent was then removed and replaced by dichloromethane, followed by addition of trityl chloride and stirring for a further 12 hours. The solvent was then removed under vacuum, and the residue was dissolved in 10 ml ethanol to give a green solution. To this solution, 3 g of Amberlist 15 ion exchange resin was added to obtain a pale green acidic solution.

Example 11

This example demonstrates the polycondensation of linear polydiorganosiloxanes in the presence of the catalyst prepared in Example 10 above.

1 kg of α,ω-dihydroxy-polydiorganosiloxane of general formula HO(SiMe ₂ O) _n H, wherein n has a value from about 4 to about 40, is added to the reaction vessel and heated to 100°C to remove any excess water. 30.5 g of 10 centipoise trimethylsilyl-dimethylsiloxane capping agent was added, followed by the 20 ppm, 1.6 ml catalyst solution prepared in Example 10 above (0.25 g in 20 ml ethanol, 0.0125 g /ml). The reaction proceeds rapidly, monitoring the loss of silanol and changes in viscosity. After 20 minutes of reaction, the viscosity was 36500 centipoise.

Example 12

This example shows the preparation of another illustrative catalyst material, H ⁺ {CB ₁₁ H ₁₂ } ^- .

0.327 g of {NHMe ₃ } ⁺ {CB ₁₁ H ₁₂ } ^- was dissolved in ethanol to a total volume of 25 ml, followed by the addition of 0.5 g of Amberlist 15 ion exchange resin. Occasional shaking of the solution over 2 hours and testing with usual dipstick showed an acidic solution.

Example 13

This example demonstrates the polycondensation of linear polydiorganosiloxanes in the presence of the catalyst prepared in Example 12 above.

1 kg of α,ω-dihydroxy-polydiorganosiloxane of general formula HO(SiMe ₂ O) _n H, wherein n has a value from about 4 to about 40, is added to the reaction vessel and heated to 100°C to remove any excess water. 30.5 g of 10 centipoise trimethylsilyl-dimethylsiloxane capping agent was added, followed by the 20 ppm, 1.6 ml catalyst solution prepared in Example 12 above (0.327 g in 25 ml ethanol, 0.01308 g /ml). The reaction proceeds rapidly, monitoring the loss of silanol and changes in viscosity. The silanol measurement showed a minimum after 60 seconds.

Claims (2)

1. a method of condensing that contains the compound of silicon bonded hydroxy or alkoxyl group is characterized in that the compound that contains silicon bonded hydroxy or alkoxyl group is selected from one or more following compounds: have general formula HO (SiMe ₂O) _nThe α of H, alpha, omega-dihydroxy-polydimethylsiloxane, wherein Me represents that the numerical value of methyl and n is 4-40; Has formula M e ₃SiO (SiMe ₂O) _nSiMe ₃Polydimethylsiloxane, wherein Me represents that the numerical value of methyl and n is 0-100; Oxyethyl group dimethyl vinyl silanes; Methoxyl group dimethyl hexenyl silane; And diethoxymethylvinylschane;

And this method was carried out in comprising in the presence of proton and the anionic catalyzer of 1-500ppm, and this negatively charged ion is { B (C ₆F ₅) ₄} ^-, { B (C ₆(CF ₃) ₂H ₃) ₄} ^-Or H ⁺{ B (C ₆F ₅) ₃CNB (C ₆F ₅) ₃} ^-

2. according to the process of claim 1 wherein by adding the alkylamine catalyst neutralisation.